This document details the features and functions of the CDP68HC68T1 CMOS Serial Real-Time Clock With RAM and Power Sense/Control product
The CDP68HC68T1 is a CMOS serial real‑time clock that provides time/calendar functions, a 32‑byte static RAM, and a 3‑wire SPI interface. It can be driven by an on‑board crystal (32 kHz, 1 MHz, 2 MHz, or 4 MHz) or an external clock source ranging from 32 kHz to 60 Hz. The device supports 12‑hour or 24‑hour mode, an alarm, periodic interrupts, and power‑fail detection, with a programmable output that can generate seven selectable frequencies.
The datasheet includes pin‑out diagrams for PDIP and SOIC packages, absolute maximum ratings, electrical specifications, functional block diagrams, register maps, and detailed descriptions of the clock/calendar, RAM, alarm, watchdog, and power‑control functions. Ordering information and package dimensions for both PDIP and SOIC variants are also provided.
| Standby (Timekeeping) Voltage | +2.2 V to +6.0 V |
|---|---|
| Operating Temperature Range | -40 °C to 85 °C |
| Static RAM Size | 32 × 8 bits |
| Number of Pins | 16‑lead PDIP / SOIC |
| Interrupt Modes | Three (Alarm, Periodic, Power‑Down Sense) |
It includes a static RAM of 32 words by 8 bits (32 × 8 bits).
Three independent interrupt modes are provided: Alarm, Periodic, and Power‑Down Sense.